1. Field of the Invention
The present invention, in general, relates to solenoid types of motors and, more particularly, to a floating armature type of an electric motor and method of assembly.
These types of electric motors are, in general, known and are sometimes referred to as a ring motor, a ring rotor, a floating armature motor, or a rotating solenoid motor.
In general, a circular rotor, also called an armature, fits inside a series of spaced-apart coils. The coils, when periodically energized, act as electromagnets. The rotor (or armature) includes an open center. The rotor includes a ferric material and by a sequential, pulsed energizing of the coils, the ferric material is urged in one direction or the other by magnetic attraction.
By periodically de-energizing the coils, inertia is used and continues to move the rotor sufficiently far so that a subsequent re-energizing of the coils will continue to urge the rotor to move in the same direction. This process is repeated to cause the rotor to turn continually and to function as an electric motor.
However, torque and efficiency in prior art designs has suffered for a variety of reasons, a few of which are described briefly, hereinafter.
It is possible to dispose three or more gears in cooperation with gear teeth attached to the rotor in order to secure the rotor in position and to extract useful energy (i.e., rotary motion) from the rotor.
A thin motor with relatively high torque is provided by certain of the prior art designs. While certain of these benefits are known, this type of a device has been difficult to build. Also, performance, output, torque and efficiency have been limited. These obstacles have prevented widespread use of this general type of motor design.
For example, it is especially difficult to manufacture and dispose a plurality of coils around a contiguous type of a rotor that includes a plurality of sequential ferric elements. It has been necessary, previously, to secure the coils to a housing in a precise way.
With prior art designs, the coil may include a shell that is split in half, disposed around the rotor, and then wound while it is disposed around the rotor.
Also, according to prior art designs the spacing of the coils around the rotor and their attachment to the housing must be precise. Furthermore, a way of sensing rotor position with respect to the housing (i.e., the coils) is also required. This positional information is then used to energize a coil for a period of time. Then a “best guess” is used to determine when to de-energize the coil.
If the speed of the motor is low, then the coil is energized for too short of a period of time. This means that the rotor is asked to “coast” before a center of the ferric element has reached a midpoint in the coil. This is the ideal time to de-energize the coil and to then allow the rotor to coast (or to possibly energize another coil that includes another ferric element that is approaching it).
Consequently, too short a period of time for coil energizing decreases horse-power output, torque, and motor efficiency.
Conversely, if the speed of the motor is high, then the coil is energized for too long a period of time. This causes the midpoint of the ferric element to pass beyond the midpoint of the coil before de-energizing of the coil occurs. When this happens (i.e., when the center of the ferric element passes beyond the midpoint of the coil and therefore beyond the midpoint of the magnetic field), the electro-magnetic field that is produced by the coil immediately begins to apply a force to the ferric element in an opposite direction with respect to the inertial movement of the rotor.
This, in turn, attempts to slow the rotor down for as long as the coil remains energized. It also robs torque and power rendering the motor with poor torque, power output, and low efficiency. Additionally, it limits maximum speed (rpm) for similar prior-art designs to low speeds.
Accordingly, these types of problems have plagued the related prior art types of electric motors and that is why they have seen limited use and have not been produced in significant quantity.
Accordingly, there exists today a need for a floating armature electric motor and method of assembly that helps to ameliorate the above-mentioned difficulties.
Clearly, such an apparatus and method of use would be useful and desirable.
2. Description of Prior Art
Similar types of electric motors are, in general, known. For example, the following patents describe various types of these devices:
U.S. Pat. No. 6,252,317 to Scheffer et al. Jun. 26, 2001;
U.S. Pat. No. 4,291,248 to Rainbolt, Sep. 22, 1981;
U.S. Pat. No. 4,214,178 to Tippner, Jul. 22, 1980;
U.S. Pat. No. 3,665,227 to Busch, May 23, 1972;
U.S. Pat. No. 1,068,531 to Rhodes, Jul. 29, 1913;
U.S. Pat. No. 741,325 to Gibbs, Oct. 13, 1903; and
U.S. Pat. No. 517,858 to Greenfield, Apr. 10, 1894.
While the structural arrangements of the above described devices may, at first appearance, have similarities with the present invention, they differ in material respects. These differences, which will be described in more detail hereinafter, are essential for the effective use of the invention and which admit of the advantages that are not available with the prior devices.